Teaching an Old Dog New Tricks

So the past two weeks, it's been cold in Finland. Like colder than -20. It usually takes me longer to get the kids dressed than the time we actually spend outside!!! However, the cold weather has one advantage - I can just let Tucker outside without a cord or a leash, he does his business and then immediately comes to the door and starts barking for me to let him in.
In the summertime, if I would do that, he'd take off and not come home.
I'm using this opportunity to give him praise and treats when he does come back, so that perhaps this new trick will continue when it gets nice out. But I'm not holding my breath...